I downloaded the Kolor Eyes viewer to test a 360° video I made, and it plays my small version fine (mp4-H264, 1024x512 29fps ~1500kb/s. But it doesn't play my full-res video, which is mp4-H264 2688x1344 29 fps 15 000 kb/s.

The full-res video plays fine in vlc and Osmo, but doesn't play in krpano or Color Eyes. Is my bitrate the issue, or the resolution, or something else?

Kolor Eyes can use two different video backends on Windows :- WMF : it will play only videos that Windows Media Player can play. So on Windows 7 it is limited to 1920*1080. On Windows 8 it can play 4K.- DirectShow : it will use DirectShow filters to decode videos. So you must have compatible codecs with DirectShow.